Electric switch



March 27, 1934. v APPLE 1,952,405

I ELECTRIC SWITCH Filed Jan. 23, 1930 Z0 I 4x l INVEN'I'OR. t Vincent\flppie ATTORNEYS ing elements.

Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE ELECTRIC SWITCHcorporation of Illinois Application January 23, 1930, Serial No. 422,752

Claims.

My invention relates to electric switches, and has particular referenceto a switch in which is incorporated a resistance element.

An object of my invention is to eliminate the 5 necessity of providing aseparate unit, perhaps in the form of a rheostat, when it is desirableto insert varied resistance in an electric circuit. This is oftennecessary where modern electric brakes are used on an automotive vehicleand 19 varying current strengths are essential to produce varied degreesof braking power.

Heretofore a circuit has been closed through electric brakes with aconventional electric switch and an independent unit in the form of a 5carbon pile rheostat, or the like, for varying the current strength.through the electric brakes in proportion to the effort exerted upon thebrake pedal.

My inventive concept resides in the utilization of the switch member perse to produce a plurality of stages of amperage in the electric circuitwith a given voltage.

A further object of my invention is to so design this combination thatupon initial movement of the switch button an electric circuit is made,

including a resistance element which is a portion of the switch unitperse. Upon further movement of the switch, this resistance element isshunted out and the current flow permitted in its full strength.

Further objects and meritorious features of my invention will becomeapparent from the following description, taken in conjunction with thedrawing wherein like numerals refer to like 7 5 parts throughout theseveral figures and wherein:

' '40 which my switch is utilized in conjunction with an electric motorand storage battery.

Numeral 10 designates the housing for my switch elements, and to thishousing is secured the cover 12 which encloses the various operat- Theterminals 14 and 16 are secured in place by means of the nuts 18 andinsulated from the housing 10 by insulation strips 20 and 22.

A contact plate 24 is secured loosely on the rod 1.50 26 and insulatedtherefrom by means of the washers 28. This contact plate is normallyheld in open circuit position, that is, out of contact with the members14 and 16, by means of the balanced springs 30 and 32. A tubular member7 5.5 34, over the outer extremity of which is telescopically mounted acap 36, encloses the spring 30 and the rod 26.

soldered to the plate 24 and the terminal 38 is a metal strip 40. Thismetal strip is insulated by the strips 42 and constitutes a conductorfrom the contact plate 24 to the resistor element which I have indicatedby the numeral 44. There is no particular type of resistance which needbe utilized in conjunction with this assembly, and for that reason Ihave indicated it broadly with a single numeral. This resistor element44 is connected to the terminal 18 and thus makes an electricalconnection from the terminal 38 to the terminal 18.

As will be noted from Fig. 1 the contact member 14 is disposed closer tothe contact plate 24 than is the contact member 16. It is thus apparentthat on depression of the pedal stem 26 the contact plate 24 will firstcome into contact with contact member 14, thus creating a circuitthrough the terminal 14, plate 24, strip 40, terminal 38, resistorelement 44, and back to terminal 18. On iurther depression of the pedal,or switch stem 26, the plate 24 will contact the contact member 16, thusshort circuiting the resistor, or shunting it out of circuit, andpermitting the full current to flow in the circuit.

Operation of my switch member is apparent from the foregoingdescription, and it is obvious that when the terminals 14 and 16 arehooked up with any desirable electric brake power mechanism, variedamperages may be made to flow through such power mechanism and thusapply varying brake pressure. Although I have illustrated the insertionof but one resistor element in my combination switch device Icontemplate the possibility of inserting others and thus permittingstill a greater number of amperage stages in the circuit.

Having illustrated a preferred embodiment of my invention various otherswill be apparent to those skilled in the art, and for that reason Ilimit myself only within the scope of the appended claims.

I claim:

1. An electric switch having a casing, a stem slidable therethrough, acontact bridge carried by said stem within the casing, a pair ofcontacts supported within the casing at unequal distances above saidbridge, a resistance connected with the contact more remote from thebridge, a third contact supported within the casing underneath saidbridge and connected with the resistance, means normally holding saidbridge out of contact with the pair of contacts and in contact with saidthird contact underneath the bridge, said stem being slidable to movethe bridge into contact with the nearest of said pair of contacts whileremaining in contact with the contact underneath the bridge and beingmovable further in the same direction to cause the same to bridge thepair of contacts.

2. An electric switch having a casing, a stem slidable therethrough, abridge contact member carried by said stem within the casing, a pair ofcontacts supported within the casing at unequal distances from saidbridge member, a resistance connected with the contact more remote fromthe bridge member, a third contact supported within the casing andconnected with the resistance, means normally holding said bridge memberout of engagement with the pair of contacts and in engagement with saidthird contact, said stem being slidable to move the bridge intoengagement with the nearest of said pair of contacts while remaining inengagement with said third contact, said bridge being movable further inthe same direction to cause the same to connect the pair of contacts.

3. In an electric circuit, a switch comprising a control member, aswitch blade supported thereon, a pair of contacts spaced unequaldistances from said blade, a resistance connected with the more remoteof said pair of contacts, a third contact connected with the resistance,means holding said switch blade out of engagement with said pair ofcontacts and in engagement with said third contact, said switch bladebeing movable to establish contact first with one of said pair ofcontacts and then with the other, said third contact adapted to maintainits contact with said switch blade during movement of the blade in theestablishment of contact with the first of said pair of contacts.

4. In an electric circuit, a switch comprising a casing, a switch bladetiltably supported within the casing, a pair of contacts spaced unequaldistances from said blade, a resistance connected with the more remotecontact of said pair, a third contact connected with the resistance,means supporting said blade normally out of contact with said pair ofcontacts and normally in contact with said third contact, said switchlade being movable to establish contact first with the nearest of saidpair of contacts and then under continued movement to tiltably establishcontact with the more remote of said pair of contacts, said thirdcontact member being adapted to follow said switch blade in its movementin making contact with the nearest of said pair of contacts.

5. In an electric circuit, a switch having a tiltably supported switchblade, a pair of contacts spaced unequal distances therefrom, meansyieldably holding said blade normally out of contact with said pair ofcontacts, said blade being movable to establish contact successivelywith the contacts of said pair and adapted to tilt to establish contactwith both contacts of the pair,

a resistance connected with the contact of said pair which is moreremote from the blade, a third contact connected with the resistanceand. 195 comprising a spring member adapted normally to contact theswitch blade in the normal position of the blade and adapted'to followthe blade and retain contact therewith during the movement of the bladeto establish contact with the nearest of the pair of contacts.

VINCENT G. APPLE.

